Brave Arms is an action game that was in early development stages at Namco’s Project Aces team, planned for the Playstation 3. We dont know how much work went into the game, as the only documents about it’s existence are a couple of scans (?) that shown some target renders and concept arts, probably created to pitch the project. As far as we can get from the japanese translation (@ Wikipedia), Brave Arms took place in Gran Rugido, the capital of the Kingdom of Sapin, an allegory of Spain in the Ace Combat series. The player would had fight alongside the local resistance against an unknown military regime.
There are no more info on Brave Arms and it’s currently unknown why it was never finished.